Cathode ray tube character mask with plurality of perforations for each character

ABSTRACT

A cathode ray tube for displaying characters and the like is provided with a character forming means comprising a character substrate provided with a plurality of character pattern perforations arranged in the form of characters, a plurality of parallel X-axis electrode elements each having a plurality of perforations and a plurality of parallel Y-axis electrode elements each having a plurality of perforations and these X- and Y-axis electrode elements are arranged in a matrix so that a desired character pattern region is determined by selecting the matrix coordinates of the electrode elements to shape the electron beam passing through the region by the character perforations of the character substrate.

CATHODE RAY TUBE CHARACTER rivers-"- Q1 3,55% si 51 Mar. 21, 19722,862,144 ll/i968 McNaney ..3 l3/86 KM X 2.965.801 l2/l960 Archer et al"313/86 X 3,i98.976 8/1965 Starr ..3l3/86 KM Primary Examiner- RobertSegal Au0rneyChittick, Pfund. Birch, Samuels & Gauthier [57] ABSTRACT Acathode ray tube for displaying characters and the like is provided witha character forming means comprising a character substrate provided witha plurality of character pattern perforations arranged in the form ofcharacters, a plurality of parallel X-axis electrode elements eachhaving a plurality of perforations and a plurality of parallel Y-axiselectrode elements each having a plurality of perforations and these X-and Y-axis electrode elements are arranged in a matrix so that a desiredcharacter pattern region is determined by selecting thematrixscoordinates of ,.the. electrode elements to .=shape the electronbeam passing through the region by the character perforations of thecharacter substrate.

5 Ciairns, 5 Drawing Figures b X i i FIG. 3

FIG.

YIYZYE o I I I ll PATENTEDmm m2 x| x2 A B0 V-INVENTOR s ATTORNEY I I I l1 s l eoccccoo 5 i ii iii TADASHI NAKAMURA YOSHIMASA YAMANAKA SHIGEAKITANAKA W- mu? CATHODE RAY TUBE CHARACTER MASK WITH PLURALITY OFPERFORATIONS FOR EACH CHARACTER BACKGROUND OF THE INVENTION Thisinvention relates to a novel cathode ray tube for displaying characters,numerals patterns and symbols (hereinafter merely termed as characters).

Among heretobefore proposed cathode ray tubes for displaying charactersmay be mentioned the Typotron and Charactron. However, as these priorcathode ray tubes utilize deflecting electrodes for selecting charactersstrict accuracies are required to fabricate their electron guns, thusrendering difficult to manufacture them.

SUMMARY OF THE INVENTION It is an object of this invention to provide anovel Cath d ray tube wherein it is possible to readily display thedesired character with the desired size on the desired position of thefluorescent screen.

According to this invention there is provided a cathode ray tube fordisplaying characters and the like comprising a' cathode electrode foremitting electrons, an electron lens means, a deflection means and acharacter forming means disposed between the cathode electrode and theelectron lens means. The character forming means comprises a charactersubstrate provided with a plurality of character pattern per forationswhich are arranged in the form of characters, a X- axis selectorelectrode including a plurality of X-axis electrode elements each havinga plurality of perforations for passing electrons and a Y-axis selectorelectrode including a plurality of Y-axis electrode elements each havinga plurality of perforations for passing electrons, said X- and Y-axiselectrode elements being arranged in a matrix so that a desiredcharacter pattern region is determined by selecting the matrixcoordinates of the electrode elements to shape the electron beam passingthrough the region by the character pattern perforations of thecharacter substrate.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawing:

FIG. 1 diagrammatically shows a longitudinal section of a cathode raytube embodying this invention;

FIG. 2 is a plan view ofa character substrate utilized in thisinvention;

FIG. 3 is a diagram to show the relationship between a character andselector electrodes for selecting the character;

FIG. 4 is an enlarged plan view of a X-axis selector electrode and FIG.5 is an enlarged plan view of a Y-axis selector electrode;

DESCRIPTION OF THE PREFERRED EMBODIMENT The cathode ray tube embodyingthis invention and diagrammatically shown in FIG. 1 comprisesanevacuated envelope 1 having a fluorescent screen 4 at one end and a neckportion surrounded by a focusing coil 3 and a deflection coil 4constituting an electron lens system. Inside the neck portion aredisposed a cathode electrode 5 of an electron gun, a grid electrode 6 inthe form of a mesh electrode to uniformly dispersing the electronsemitted from the cathode electrode 6 to have a uniform density, acharacter forming means embodying this invention and an accelaratingelectrode 8.

In accordance with this invention, when passing through the characterforming means 7 the electron current passed through the grid electrode 6is converted into an electron beam acting to form the desired character.After entering into the electron lens system, the electron beam iscaused to focus on the desired position of the fluorescent screen by theaction of the deflection coil 4 to display the desired character.

The character forming means constituting an essential element of thisinvention comprises a character substrate 9 and two selector electrodesarranged in a matrix. As shown in FIG. 2. the substrate 9 is a thin flatsheet of insulator such as mica or ceramic. The substrate is providedwith a number of perforations (character pattern perforations) arrangedin the form of numerals, alphabets or symbols. Selector electrodes aredis osed to constitute a matrix and include a X-axis selector electrode10 shown in FIG. 4 and a Y-axis selector electrode 11 shown in FIG. 5.In this example, the X-axis selector electrode 10 is disposed on thefront side of the character substrate'9 in close proximity theretowhereas the Y-axis selector electrode 11 on the rear side of thecharacter substrate in close proximity thereto. Each of these electrodesis comprised by a plurality of closely adjacent parallel electrodeelements or strips, each provided with a number of perforations forpassing electrons. I

'FIG. 4 shows an enlarged plan view of the X-axis selector electrode 10comprising a plurality of parallel electrode elements 12 which aredisposed in the same plane. Each of the electrode elements 12 is formedwith numerous perforations 13 for passing electrons.

FIG. 5 shows an enlarged plan view of the Y-axis selector.electrode.llrsimilarlycomprising a plurality ofparallel electrodeelements 14 disposed in the same plane. Each of the electrode elementsis formed with numerous perforations 15 for passing electrons. Asdiagrammatically shown in FIG. 3, electrode elements 12 and 14 aredisposed with respect to the character substrate 9 to form a matrix.Thus, by selecting some of the electrode elements of the X- and Y-axisselector electrodes it is possible to select the desired characterpattern region on the character substrate 9. For example, FIG. 3 showsthe selection of the region of a numeral 1 at the cross point between arow X1 and Y1 shown in FIG. 2 by electrode trons will not be attractedby the negative electric field. On the other hand, when both X- andY-axis selector electrodes are at a positive potential incomingelectrons will be attracted by these electrodes. As a result, byimparting a positive potential to some electrode elements of the X- andY-axis selector electrodes, electrons will be attracted by the regioncomprised by these selected electrode elements. This invention is basedon this principle as discussed in detail hereinbelow.

While electrons of uniform density pass through the grid electrode 6 inthe form of a mesh when a positive potential is impressed upon electrodeelements of X- and Y-axis selector electrodes that determine a characterpattern region of a character-to be displayed of the character substrate9, the character pattern region will create a high positive electricfield than remaining regions. The resulted field attracts electrons athigh speed toward said character pattern region. At this time, arrivedelectrons will collide against portions of the electrode elements 12 ofthe X-axis electrode 10 which are included in the pattern region andelectrons directed to the perforations 13 of electrode elements 12 willreach the character substrate with a spread corresponding to thecharacter pattern region. However, since the substrate 9 is providedwith perforations that shape the electron beam, or character patternperforations after passing through substrate 9 the electron beam patternwill be given the given configuration of the selected character. Afterpassing through perforations 15 of electrode elements 14 of the Y-axisselector electrode 11 the electron beam will be accelerated by theaccelerating electrode 8 shown in FIG. 1 toward the fluorescent screen2. The cross section of the electron beam impinging upon the fluorescentscreen corresponds to the configuration of the character patternperforations of the character substrate 9. so that the selectedcharacter will be displayed on the screen 2. The position and magnitudeofthe displayed character are determined by the focusing coil 3 and thedeflection coil 4. By successively exciting the character selectorelectrodes it is possible to simultaneously display a number ofcharacters on the screen 2 by utilizing its residual pro erty.

While in the above described embodiment the X-axis selector electrodeand the Y-axis selector electrode are positioned on the opposite sidesof the character substrate it should be understood that this inventionis not limited to this particular arrangement but X- and Y-axis selectorelectrodes may be fabricated, i ctese roximity to form a matrix and theeharacter substrate may be positioned on the front or rear side of theassembly. it will also be clear that it is desirable to align as far aspossible numerous perforations l3 and of electrode elements 12 and 14when they are assembled to form the matrix.

As above described. in accordance with this invention thecharacterpattern.perforationsprovided for-thecharactersubstrate and thepattern region of the character pattern perforations are selected by theselection of the matrix coordinates comprised by the X- and Y-axisselector electrodes thereby displaying the desired character.Accordingly the construction of the novel display cathode ray tube ismore simple than con ventional display devices.

What is claimed is:

l. A cathode ray tube for dis laying characters, numerals and patternscomprising a cathode electrode for emitting electrons, a grid meshelectrode for uniformly dispersing electrons emitted from said cathode,an electron lens means, a deflection means, and a character formingmeans disposed between.

said cathode electrode and said electron lens means, said characterforming means being characterized by comprising a character substrateprovided with a plurality of character pattern perforations which arearranged in the form of characters, and providing for each of saidcharacter pattern perforations an X-axis selector electrode including aplurality of X- axis electrode elements each having numerousperforations for passing electrons and a Y-axis selector electrodeincluding a plurality of Y-axis electrode elements each having numerousperforations for passing electrons, said X- and Y-axis electrodeelements being arranged in a matrix so that a desired character patternregion constituting numerous elemental beams is determined by selectingthe matrix coordinates of said electrode elements to shape the electronbeam passing through said region by the corresponding said characterpattern perforation of said character forming substrate.

2. The cathode ray tube according to claim 1 wherein said charactersubstrate is a thin sheet of insulator.

3. The cathode ray tubeaccording to ,claim 1 whereinsaid X- and Y-axisselector electrodes are disposed on the opposite sides of said charactersubstrate but closely spaced therefrom.

4. The cathode ray tube according to claim I wherein said X- and Y-axiselectrodes are assembled in close proximity to form a matrix and theassembly is positioned one side of said character substrate.

5. The cathode ray tube according to claim 1 wherein the characterpattern perforations of said character substrate and perforations ofsaid X- and Y-axis electrode elements align with each other when theyare assembled.

PO-1O5OI UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PatentNo. 3I65l'36-l Dated March 1972 Shigeaki Tanaka; Yoshimasa Tamanaka; InVnt Tadashi Nakamura It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below Column 2, line 33, before"Yl." insert a columnSigned and sealed this 1st day of August 1972.

(SEAL) Attest:

EDWARD M. FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents

1. A cathode ray tube for displaying characters, numerals and patternscomprising a cathode electrode for emitting electrons, a grid meshelectrode for uniformly dispersing electrons emitted from said cathode,an electron lens means, a deflection means, and a character formingmeans disposed between said cathode electrode and said electron lensmeans, said character forming means being characterized by comprising acharacter substrate provided with a plurality of character patternperforations which are arranged in the form of characters, and providingfor each of said character pattern perforations an X-axis selectorelectrode including a plurality of X-axis electrode elements each havingnumerous perforations for passing electrons and a Y-axis selectorelectrode including a plurality of Y-axis electrode elements each havingnumerous perforations for passing electrons, said X- and Y-axiselectrode elements being arranged in a matrix so that a desiredcharacter pattern region constituting numerous elemental beams isdetermined by selecting the matrix coordinates of said electrodeelements to shape the electron beam paSsing through said region by thecorresponding said character pattern perforation of said characterforming substrate.
 2. The cathode ray tube according to claim 1 whereinsaid character substrate is a thin sheet of insulator.
 3. The cathoderay tube according to claim 1 wherein said X- and Y-axis selectorelectrodes are disposed on the opposite sides of said charactersubstrate but closely spaced therefrom.
 4. The cathode ray tubeaccording to claim 1 wherein said X- and Y-axis electrodes are assembledin close proximity to form a matrix and the assembly is positioned oneside of said character substrate.
 5. The cathode ray tube according toclaim 1 wherein the character pattern perforations of said charactersubstrate and perforations of said X- and Y-axis electrode elementsalign with each other when they are assembled.